New Eczema Drug Approved

Darrell Hulisz, RPh, PharmDVictoria Cho, Pha

January 1, 2017

The FDA recently approved a novel drug, crisaborole (Eucrisa), for the treatment of mild to moderate AD in adults and children greater than the age of two. This topical ointment is a phosphodiesterase 4 enzyme inhibitor that helps reduce symptoms of itchiness and inflammation caused by atopic dermatitis, which is also known as eczema.

Atopic dermatitis (AD) affects about 10-20% of children world-wide. Although it is more common in children, adults can still be diagnosed with AD. Some of the hallmark symptoms include itchiness, redness, and dry skin; however, this is different from psoriasis. Psoriasis has more of a plaque appearance and a quick turnover of cells. Pruritus associated with AD can adversely impact a patient's quality of life, including insomnia due to the itchiness, and chronically irritated dry skin. AD can also be associated with other atopic disorders, such as asthma and allergic rhinitis.

According to guidelines from the American Academy of Dermatology, there are non-pharmacologic interventions that can be implemented to reduce the severity of AD, such as moisturizing the skin and avoiding the use of harsh cleansers when bathing. Wet-wrap therapy can also help reduce the AD severity. By providing a wetted first layer of topical agent covered by a dry layer, this method helps occlude the topical agents for better absorption, minimize loss of water, and protect the patient from scratching. These are simple treatment options pharmacists can suggest when patients are requiring treatment for AD especially in younger children.

Currently, in the guidelines, there are two main pharmacologic drug classes used to treat AD: topical corticosteroids and topical calcineurin inhibitors. Topical corticosteroids range from very high potency, such as clobetasol propionate, to lowest potency such as hydrocortisone. Topical corticosteroids are first line therapy after a patient has failed to treat lesions with the non-pharmacologic interventions. The higher potency topical corticosteroids are used for acute flares of AD for short term treatment, while the lower potency is used for long-term management of AD. As for second-line therapy for shorter-term, non-continuous treatment, tacrolimus and pimecrolimus are effective topical calcineurin inhibitors used to treat AD. Generally, topical calcineurin inhibitors are used when a patient is refractory to topical steroids, or when chronic use topical steroids results in skin atrophy and/or telangectasia. There are black box warnings for increased risk of malignancy with these agents. Topical calcineurin inhibitors are also not recommended in children under the age of two.

The approval of crisaborole (Eucrisa) gives clinicians another option for treatment of mild to moderate AD in adults and children greater than age of two. While crisaborole works as a phosphodiesterase 4 enzyme inhibitor, the exact mechanism for AD is unknown; however, it may be related to inhibition of cutaneous neuron and dorsal root ganglion neuron activity. Based on two phase III studies, crisaborole has minimal side effects and associated with application site pain such as burning and stinging, in addition to vomiting. In comparison to vehicle treatment patients, crisaborole-treated patients improved more in terms of Investigator's Static Global Assessment (ISGA), percentage of patients achieving clear/almost clear status, reduction in severity of symptoms of AD, and time to improvement of itchiness. Based on patient's IGSA score, more crisaborole treated patients scored "clear to almost clear" around day 29. Overall, crisaborole is shown to be efficacious in treating patients including children with AD.

In conclusion, crisaborole appears to be a potentially useful treatment for AD in patients concerned about long-term side effects of topical corticosteroids and calcineurin inhibitors. Currently, crisaborole has not been studied in patients under the age of two, but future studies may show efficacy in children this population since AD does occur in this age group. The cost of crisaborole is unavailable at this time, but the product should be available in early 2017.